Comets travel in orbits around the sun. some comets take less than 200 years to orbit the sun. they are called short-period comets. short-period comets are thought to originate in the kuiper belt, which is a belt of icy objects just beyond the orbit of the . the dwarf planet located in this belt.
1.a: earth
b: jupiter
c: mercury
d: neptune

2.a: neptune
b: pluto
c: saturn
d: uranus

Comets travel in orbits around the Sun. Some comets take less than 200 years to orbit the Sun. They are called short-period comets. Short-period comets are thought to originate in the Kuiper Belt, which is a belt of icy objects just beyond the orbit of the planet NEPTUNE. The dwarf planet PLUTO is located in this belt.  

Explanation:

Comets are composed of ice, dust and gas. Comets are categorized into two kinds: short period comets (P < 200 years) which come from Kuiper belt and long period comets (P >200 years) come from Oort clouds.

Kuiper belt resides beyond the orbit of the planet Jupiter. Kuiper belt contains many objects Comets, asteroids and dwarf planets. Pluto which is a dwarf planet is located in Kuiper belt.  Earlier it was considered as a planet but demoted to a dwarf planet in 2006.

the answer is b.) hydrogen bonds between bases.